Project Infiniti G20 Racecar: More Power
By Steve Rockwood
Road racing is a thrill that has few equals in the wide world of wheels. Drag racing, unless you're talking nitro cars, is a thrill that quickly loses its lustre. Losing a drag race while road racing, however, is an exercise in abject frustration. Nothing will make you hate your car more than nailing that apex and throttle point perfectly to extract every ounce of momentum coming out of the corner, only to watch your opponent sail right past you on a long straightaway and park it in front of you in the next corner. Project G20 Racecar's tired engine, with over 130,000 miles on it, was destined to only let us down. We needed to fix it.
Check out the rest of our Project Infiniti G20 Racecar build here!
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| Project G20 about to lose a drag race. |
Before we dig in to what is really a Part 1 of our quest for more power, we need to caveat this article with the fact that this car was originally set up for the now defunct NASA SE-R Cup. The SE-R Cup had open engine modifications, with the only real rules being that you had to retain the stock engine in its normally aspirated form, and could not have less than 16 lbs per horsepower measured at the wheels. The rules were written in this manner to allow anyone with a junkyard engine, and a few breathing mods, to compete with the guys who treat racing like Gran Turismo and rebuild their motors twice a season. It worked. Quite well, in fact, as perennial winner Tom Paule hammered on his junkyard engine with absolute impunity for many seasons before defecting to the Honda Challenge once SE-R Cup went kaput. That car would likely still turn a competitive lap time for that series. Our car then transferred into NASA's Performance Touring (PT) series, which assigned a points value to every modification, and then classed your car based on the original car, and how recognizable it is from its original form (your total modification points). Needless to say, the rules kept us in a stock engine, with a stock head, and breathing on its own. With our state of mods, our car slotted in as a fully optioned PTE car, or a PTD car with room for improvement.
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| Project G20 in full SE-R Cup livery. |
The first, and most obvious, modification under the hood of Project G20 was a beautiful all-stainless header from now-defunct Hotshot Performance. With stepped primaries whose length was optimized for the more aggressive cams available for the SR20, short secondaries, and a 3″ collector, this header was as close as you could get in power production to a custom-fabbed full race header. Hotshot built this header as an answer to cheap knockoff companies copying their original design – these unscrupulous companies' headers fit on Hotshot's jig to perfection. Unfortunately, the SR20 performance aftermarket's ship had sailed by this point, and Hotshot only made a few for some very lucky customers. This header has served us quite well over the years, and has even survived a direct hit (well, after some minor repairs) from a freshly liberated connecting rod and subsequent engine fire. Not a single crack has developed, despite the severe heat cycling found in racing, and we sorely miss the days when you could get a mass-produced (well, relatively) all stainless header with stepped primaries for under $600. RIP, Hotshot.
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| The Hotshot Gen VI header was truly a work of art. If it were still a product you could buy from a vendor, rest-assured it would be MotoIQ Certified Legit. |
Our Hotshot header dumps into a custom 3″ race exhaust built from a 3″ aluminized Walker resonator and a mild steel U-bend fabricated by your humble author. Building a racecar exhaust is generally a simple affair: make it exit somewhere behind the driver, point it away from the car, and if you've got the room/weight to spare, try to shut it up some. While our setup was by no means quiet, it did succeed in keeping our ears from bleeding with earplugs on. One thing to consider when building an exhaust for your racecar: don't make your exhaust too quiet. Keep in mind that you're probably sharing the track with a number of other cars in different classes, driven by drivers who may or may not notice you next to them. Having a loud exhaust will almost always notify your fellow racers that you're next to them. Just keep in mind that, like the turn signal, you can inform others of your presence, but it's still up to them to do something with this information.
